SOLAR-1
Trial question
What is the role of alpelisib/fulvestrant in patients with HR+/HER2- advanced breast cancer?
Study design
Multi-center
Double blinded
RCT
Population
572 patients (571 female, 1 male).
Inclusion criteria: patients with HR+/HER2- advanced breast cancer who had previously received endocrine therapy.
Key exclusion criteria: receipt of chemotherapy previously for advanced disease; receipt of previous fulvestrant therapy; receipt of any PI3K/Akt/mTOR inhibitor; inflammatory breast cancer at screening; Child Pugh B or C; T1DM or uncontrolled T2DM.
Interventions
N=284 alpelisib plus fulvestrant (alpelisib 300 mg/day plus fulvestrant 500 mg every 28 days and once on day 15).
N=288 placebo plus fulvestrant (matching placebo plus fulvestrant 500 mg every 28 days and once on day 15).
Primary outcome
Median progression-free survival in PIK3CA-mutated population
11 months
5.7 months
11.0 months
8.3 months
5.5 months
2.8 months
0.0 months
Alpelisib plus
fulvestrant
Placebo plus
fulvestrant
Significant
increase ▲
Significant increase in median progression-free survival in PIK3CA-mutated population (11 months vs. 5.7 months; HR 1.54, 95% CI 1.18 to 2).
Secondary outcomes
No significant difference in median progression-free survival in population without PIK3CA mutation (7.4 months vs. 5.6 months; HR 1.18, 95% CI 0.8 to 1.72).
Safety outcomes
No significant difference in any adverse events.
Conclusion
In patients with HR+/HER2- advanced breast cancer who had previously received endocrine therapy, alpelisib plus fulvestrant was superior to placebo plus fulvestrant with respect to median progression-free survival in PIK3CA-mutated population.
Reference
Fabrice André, Eva Ciruelos, Gabor Rubovszky et al. Alpelisib for PIK3CA-Mutated, Hormone Receptor-Positive Advanced Breast Cancer. N Engl J Med. 2019 May 16;380(20):1929-1940.
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